Add pointfree Pair to array (pairToArray) function

[kierans]

Is your feature request related to a problem? Please describe.

Most other Monads have a pointfree version of the toArray method.

• List -> listToArray
• Tuple -> tupleToArray

However there is no pairToArray function

Describe the solution you'd like
A pairToArray function

Describe alternatives for how you do this now

(p) => p.toArray()

Code
Do you have example code or tests in a Repl for what you'd like added?

Additional context
Add any other context or screenshots about the feature request here.

I'm happy to give implementing this a go if the maintainers think it's worthwhile/will actually merge the changes 😄